1. Field of the Invention
This present invention relates to a hinge device, and more particularly to a damping hinge device preferably applicable to folding or unfolding an electric device such as a folding mobile phone, a portable computer and an electric pocket notebook.
2. The Related Art
Conventionally, a portable apparatus, such as a portable computer and a folding mobile phone, has a body and a display joined by two hinges arranged in two sides of the portable apparatus.
Referring to FIG. 1, a traditional hinge 10 includes a housing 3, a sliding cam 5, a rotating cam 6, a spring 4, a shaft 7, an E-ring 8 and a washer 9. Two curving surfaces 51 are formed in an upper end of the sliding cam 5, the curving surfaces 51 show a V-shape. Two sliding portions 61 are formed in a lower end of the rotating cam 6. The sliding cam 5 and the rotating cam 6 are accepted in the housing 3, the two sliding portions 61 is rotatably against the curving surfaces 51 of the sliding cam 5. The washer 9 covers the bottom of the housing 3. The spring 4 is accepted in the housing 3, one end of the spring 4 is against the washer 9, the other end of the spring 4 is against a lower end of the sliding cam 5. A lower end of the shaft 7 forms a ring-shaped groove, the shaft 7 passes through the rotating cam 6, the sliding cam 5, the spring 4 and the washer 9, and the E-ring 8 is accepted in the ring-shaped groove of the shaft 7.
The rotating cam 6 is fixed with the display of the portable computer, the housing 3 is fixed with the body of the portable computer. Generally, the two traditional hinges 10 are arranged in the two sides of the portable computer to link the body and the display. When the portable computer is unfolded or folded, the sliding portions 61 slides along the curving surfaces 51 quickly to a lower point of the curving surfaces 51, the rotating speed of the display around the body is quick, the display and the body are easy to be destroyed. If the traditional hinge 10 is arranged in a folding mobile phone, when the folding mobile phone is unfolded or folded, a display will strike a body of the folding mobile phone, the folding mobile phone will fall off the hand of the user carelessly.